Elapsed time liquid level telementering device



y 1968 J. J. JARNAGIN 3,384,967

ELAPSED TIME LIQUID LEVEL TELEMETERING DEVICE 5 Sheets-Sheet 1 OriginalFiled Oct. 5, 1961 Fla). 8

Pie/Z INVENTOR. )osEpH l )ARMAC-HN AT ToRNEy J. J. JARNAGIN 3,384,967

ELAPSED TIME LIQUID LEVEL TELEMETERING DEVICE May 28, 1968 5Sheets-Sheet 2 Original Filed Oct. 5, 1961 INVENTOR. )OSEPH )AQNAG\N BY2- ATTORNE\/ United States Patent 3,384,967 ELABSED Ti'ME LlQUii) LEVELTELEMETERHNG DEVICE Joseph 3. .larnagin, @916 Green Manor Drive,Louisville, Ky. 40228 Original application Get. 5, 1961, Ser. No.143,258, now

Patent No. 3,248,795, dated May 3, 1966. Divided and this applicationMar. 17, 1966, Ser. No. 536,945

Claims. (Cl. 33-126.6)

ABSCT 95 THE DISCLOSURE This invention relates to the art oftelemetering of rain and water measurements and provides apparatus fortransmitting measurements of liquid levels by means of wire or radiofrom a measuring site to a central control station having means forindicating such measurements.

The invention described herein may be manufactured and used by or forthe Government for governmental purposes without the payment to me ofany royalty thereon.

This application is a division of application, Ser. No. 143,258, filedOut. 5, 1961, now Patent No. 3,248,795.

Liquid level telemetering devices are commonly used for reportingpurposes among agencies concerned with control, prevention, reporting,and study of floods and in the study and reporting of navigation andweather conditions. Water levels, tide levels and precipitation amountsare collected at various critical points and transmitted to a centralstation where these reports are collated, evaluated, and disseminated.

It is the object of this invention therefore to secure remote stream andrain gauge readings, and to transmit such information by means of wireor radio, to telemetering gauge stations.

It is a further object of this invention to provide a device, simple ofconstruction, of operation, and of maintenance, as well as inexpensiveto construct and to operate.

Another object of this invention is to provide a fluid leveltelemetering system which is easily handled and stored, yet accurate inoperation.

Another object of this invention is to provide, in a device of the typedescribed above, a new mechanical measuring means and a new electricaldata transmission means.

Briefly, this system comprises at a measuring site: communicationreception and water level measuring means as well as conventional wireor radio transmission means equipped with conventional carrier and tonegeneration equipment; and at an interrogation control center: equipmentfor carrier and tone frequency generation, control means for keying thecarrier and tone generator communication reception means and elapsedtime recording equipment.

One complete rain measurement system has at the measuring site, a tankwith a motor driven traveling probe, a receiver includin a tone controlrelay, which upon actuation from the central control point, operates theprobe motor to raise the probe through the depth of water to the watersurface. Tone generation then starts which, when received at the controlcenter, switches the supply on the recording motors from DC to AC.Subsequently, when the probe has broken the surface of the water and thetone has stopped, the supply to the recording motors is again reversedfrom AC to DC thus stopping the motors the instant the signal from thetone receivers at the measuring site is lost. In one embodiment of theinterrogation center, there is a counting system including an oscillatorconnected to a thyratron. A circuit is provided for changing ice therate of frequency of the oscillator which in turn changes the rate offiring or conduction of the thyratron. A keying relay for operating thethyratron cooperates with the tone control relay in the receiver at themeasuring site. Thus the oscillator, with counters, aifords measurementsin units of ten or one hundred depending on whether stream or rainmeasurements are being taken. Control centers include both dialmeasurement systems and counting systems.

In the stream water level detector, an electronic tube combines ahalf-Wave rectifier and an amplifier so connected that the output of therectifier portion is applied to bias the grid of the amplifier portioncausing the tube to cut off and to be in a nonconducting condition. Arelay controlling the output of the amplifier, will have been energized,prior to the cutoff of the tube, thus keying the transmitter and tonegenerator for a time determined by a time delay relay. The probe,connected to the grid of the amplifier, upon touching the water removesthe bias from the grid of the amplifier, thus permitting the tube toconduct, this in turn actuating relays to discontinue keying thetransmitter carrier and tone generator, and to reverse the probe motor.When the probe reaches the home position, DC is applied to the probemotor to insure instant positive stop at the home position and, shortlythereafter, the DC is removed from the motor by elements of the controlcircuit.

Detailed operation and further advantages of this invention will bebetter understood from the following detailed description thereof whenread in conjunction with the accompanying drawings in which:

FIG. 1 is a front View of the dial-type interrogation control panel;

FIG. 2 is a front view of a counter-type interrogation control panel;

FIG. 3 is a side view of a rain gauge used at the measuring site;

FIG. 4 is a perspective view showing the top of the rain gauge shown inFIG. 3;

FIG. 5 is a circuit diagram of the dial-type interrogation control panelshown in FIG. 1;

FIG. 6 is a circuit diagram of the counter-type interrogation controlpanel as shown in FIG. 2;

FIG. '7 is a circuit diagram of a simplified version of the speciesdepicted in FIG. 6;

FIG. 8 is a circuit diagram of an elapsed time stream water leveldetector used at the measuring site; and

FIG. 9 is a circuit diagram of an elapsed time preciptation telemeteringdevice for use at the measuring site.

Referring in more detail to PEG. 1, the gross indicator 1 is secured tohe axle of a 4 r.p.m. synchronous clock motor of the spring rewind typewhich is normally used for time delay. The motor turns counterclockwiseand the indicator reads on the inches dial 2 for rain measurement and onthe feet dial 3 for stream depth measurements. The sensitive dial 7 onthe right of the control panel 8 is marked in tenths of the unitsmeasured by inches dial 2 or the feet dial 3. it is normally used inmeasuring fractions of feet when the panel is measuring stream depth andis normally ignored when rain depth in inches is being measured, exceptwhen finite accuracy is required. The sensitive indicator 6 is securedto the axle of a rpm. synchronous clock motor and may be set at zeromanually. Also included on the face of the interrogation control panel 8is a reset button 4 and a carrier control starter button 5, detailedfunction of which will be included in the explanation of FIG. 5 below.

FIG. 2 depicts a front view of the interrogation countertype controlpanel 9. included on the panel generally from left to right is afilament transformer line voltage pilot lamp it) which indicates theline voltage taken off of the filament transformer for tube 68 describedbelow under FIG. 6. To the right of pilot lamp is starter button 11 andthe oscillator frequency change toggle switch 12. The unit reset counter13 is the full unit counter of this embodiment. The oscillator light 17,between the counters, indicates that the oscillator is working and itsfrequency of oscillation. The fraction counter 14 is a conventionalnonreset type counter. To the right of traction counter 14 is manualreset button 15, and ready light 16 indicates that the unit is ready foruse. A counter 13 appropriate for this embodiment of the control panelhas a twelve volt DC coil and is powered by a filament transformer usinga selenium full wave rectifier. The aforementioned transformer is 12volt, center tapped, connected on one side of the center tap to thefilament of tube 68 (FIG. 6), and the full winding to the rectifier topower the counter. A full explanation of the detailed working of theface of the interrogation control panel is included in the explanationof the circuit diagram dcpicted by FIG. 6.

FIGS. 3 and 4 depict in detail the rain gauge 18 resting in stand 29showing the side mounted probe motor 19 which, in this embodiment is a 1rpm. synchronous clock timer motor, the shaft for which has beenextended for the mounting of pulley 21 which is held in place on sleeveshaft 22 by screw 23. Probe 148 (FIG. 9) utilized in this embodiment(not shown in FEGS. 3 or 4) is an elongated solid metallic pointedobject of approximately the size of a ten-penny nail. It is secured toand suspended by a stainless steel wire of the type generally used inwire recording and is raised and lowered by the winding and unwinding ofthe Wire, the free end of which is secured on pulley 21. The shaft ofprobe motor 19 (which, in the embodiment depicted, is a General Electric5-minute timer No. CR2S20-l736A2, modified as described above) isdesigned for a rise of the probe of one-tenth of an inch per second.Probe 148 is normally in contact with the bottom of the container exceptwhen measurement is being made, and the probe is in motion. Electricalcontact when the probe is at rest at the bottom of the container isinsured by having a depression 149 (FIG. 9) at the bottom of thecontainer at the point of contact of the probe, which depression isfilled with mercury to level with the bottom of the container. Includedin the timer mechanism is a spiral wheel which acts as a stop limit onthe motor, permitting exact adjustment of the probe and limiting the endtravel. The timer switch of the motor is not utilized in the instantembodiment but may be incorporated as an upper limit means in the eventof improper function of the probe or, when the container is tilted oroverflowing with water, to stop the timer mechanism.

The stream gauge probe 122, not shown in the drawings, but depictedschematically in the circuit diagram of FIG. 8, is a probe similar tothat described for the rain detector, also suspended by stainless steelwire, which is raised and lowered by a pulley operated by a 200 r.p.m.capacity start and synchronously running motor. A grooved brass shaftmay be utilized for winding the wire in order to prevent overlapping ofthe wire, thus furnish ing more accurate readings. The size of shaft andthe weight of the probe is designed in the instant embodiment for a fallof one foot-per-second.

FIG. 5 depicts the elapsed time indicator and interrogation controlsystem designed to operate in conjunction with the stream level detectorshown at FIG. 8 and the rain measuring unit at FIG. 9. When springloaded starter button 5 is depressed, relay coil 24a is energized andcontacts 25a and 26a are closed (coil 24a and contacts 25:: and 26abeing part of one relay). So long as the starter button 5 is held downor depressed, the line leading to contact 25a is open, as a result ofwhich no further action takes place within the device except theenergizing of the aforesaid relay. Upon release of starter button 5, thetime delay relay comprising heater 27 (a two-second thermo delay relayamperil'c type 115 NC 2) and normally closed time delay switch 29 isenergized. Coil 28b is also encrgized for a period of two seconds andcontact 36b (on coil 28b) keys the tone generator and transmitter(through leads 209) which is used in conjunction with this device (butnot shown) for a time equal to the two second delay of the time delaycontacts. At this time DC voltage is present in the windings of themotors of indicators 1 and 6, having been converted thereto by seleniumrectifier 31 and passing from said rectifier through the resistor 35,through normally closcd contact 330 of relay coil 30c to the motors ofindicators 1 and 6. Upon receiving a signal from the measuring site,tone gencrator controlled switch 37 closes and coil 36c is energized,contact 320 of coil 3-30 closes and contact 330 of coil 38c opens thusplacing 60 cycle AC current on the windings of the indicator motors, atthe same time disconnecting the source of the DC current. Thus, duringthe reception of the signal from the measuring site, the tone generatorcontrolled switch 37 remains closed and indicators 3 and 6 measure, interms of depth of the water, the time of receipt of the signal from themeasuring site. When the signal stops, the tone generator controlledswitch 37 opens, tie-energizing relay coil 39c and oicning contact 32cwhile closing contact 330 of relay coil 36c. Thus the windings of theclock motors driving indicators l and 6 are again deprived of ACcurrent, the substituted DC voltage acting as a brake to stop the motorsinstantly. As mentioned above, the motor of gross indicator 1 is of thespring rewind type in order that it may be reset electrically simply byremoving the direct current voltage on the windings. This is done bypressing the reset button 4, the action of which also de-energizes relaycoil 24a. As mentioned in the explanation of FIG. 1, the motor ofsensitive indicator 6 is reset manually only. Condenser 34 is a twentymi, volt type. Resistor 35 is rated at 3K ohms and ten watts.

FIG. 6 shows in detail the circuit diagram of the interrogationcounter-type control panel, the front of which is shown at FIG. 2. Itwill be noted that this device serves the same purpose as the controlsystem shown at FIG. 5, except that the reading of depth is in digitsrather than in dial form and, of course, may be read with greater ease.This control system is designed to operate in conjunction with themeasuring circuits shown in FIGS. 8 and 9. The similarity of operationbetween this system and the system depicted by FIG. 5 is apparent. Thesame general method is used for keying the carrier and tone generatorand for energizing relay coil 48c which, of course, corresponds withrelay coil 300 of FIG. 5. It should also be noted at the outset that theoscillator circuit shown in this preferred embodiment is very elementaryand it is contemplated that more complex and practical oscillators orpulsers may easily be incorporated into this system. Pilot light 16through closed contact 44a is on prior to operation. When starter button11 (a spring loaded starter button) is depressed, coil 43a is energizedand contacts 41a and 42a are closed while contact 44a is opened, thelast cutting off pilot light 16. So long as starter button 11 isdepressed, the main circuit is broken and nothing further takes place.When the starter button is released, the two-second time delay heater 45begins its cycle at the conclusion of which time delay switch 46,operating on heater 45, will open. Coil 47b is energized which in turncloses the two contacts 16Gb and 167/) located thereon and shown belowwhich keys a carrier (not shown) and a tone generator (not shown)operating in conjunction with this control system through leads '74 and75, respectively. When the tone generator controlled switch 76, locatedin the receiver used in conjunction with this system is closed onreceipt of a signal from the measuring site, coil 480 is energized whichcloses contact 49c, and opens contacts 670 and 580. As contact 490closes, coil 52a! is energized by the current passing through normallyclosed contact 50a. Also as coil 43:? is energized, it will be notedthat as contact 640 (on coil 430) is closed and as contact 67c is openedthat coil 63a is placed in the plate circuit of thyratron tube 68.

Upon the energizing of coil 48c, contact 70c has closed the cathodecircuit. It will be noted that as coil 63a is placed in the circuit, thefull unit counter 13 (not shown) on leads 213 operating from the relaycontact 38a of which coil 63c is a part, is set in motion and commencesthe count.

When the tone is lost, the tone control relay '76, located in thereceiver, opens and coil 480 is tie-energized, which in turn openscontacts 4%, 640, and 7trc, at the same time closing 67c and 580,shunting resistor 39 with the normally closed contact 58c and increasingthe frequency of the oscillator. At the same time, the circuit ofnormally open contact 700 is removed from the cathode circuit ofthyratron tube 68. Coil 63c (operating full unit counter 13, not shown,through contact 38s) is removed by contact 640 (on coil 48c) and coil65f (operating digit counter 14, not shown, through contact 165 is addedby contact 670 (on coil 480) thus continuing the count at ten cycles persecond on the digit counter 14 (not shown) through leads 214 until relaycoil 52d, a SPDT 5K ohm DC relay coil times out in .9 second and opensthe cathode of thyratron tube 68. On each energization of coil 63:2, thevoltage to delay circuit coil 52d is keyed thus charging the capacitor53 to hold for another .9 second. The variable resistor 54 paralleledwith condenser 53 is the adjustment for this circuit. The fraction counton the digit counter 14 (leads 214) will increase according to thelength of time that coil 52d holds contact 69d closed keeping thecathode circuit of thyratron tube 68 closed after coil 48c has beende-energized and contact 700 has returned to the open position. Thedigit counter 14 (leads 214), during this period of time, will beindicating in tenths and hundredths for stream and rain depth,respectively. With respect to the digit counter, it should be noted thatin this embodiment, the counter works in reverse for direct reading,that is to say, from to 0. Further, with respect to the circuit diagramshown in FIG. 6, it should be noted that coil 52d, being a DC relay,requires the presence of selenium rectifier 51 between the aforesaidcoil and contact 592. Condensers 62 and 66 are .25 mf. condensers, as iscondenser 55. Condenser 57 is a .01 mf. condenser. The heater (notshown) for thyratron tube 68 is a 6.3 volt heater operating oif of theAC line. It should be noted with respect to this circuit that the digitor fraction counter and its associated components may be entirelyeliminated leaving only the full unit counter reading in tenths and onehundredths (for stream and rain, respectively). Toggle switch 12 may beused to change the frequency of oscillation of the oscillator. Thus,with the toggle switch in the open position, the full unit counter willbe indicating in feet and the digit counter will be indicating in tenthsof feet when measuring stream depth, and these indicators would, withthe toggle switch in this position, be indicating in tenths and onehundredths of inches, respectively, when measuring rain depth. Withtoggle switch 12 in the closed position, the full unit counter will bemeasuring in tenths of feet of stream depth and one hundredths of inchesof rain depth while, at the same time, the digit counter will bemeasuring in terms of one hundredths of feet when measuring streamdepths and a fraction so delicate as to be ignored when measuring raindepth. This follows from the inclusion or exclusion of the resistor 39in the circuit (with resistor 59) as the toggle switch 12 is opened orclosed, respectively. The frequency of oscillation of the oscillator(power for which is supplied through leads '77), is made apparent on theface of the control panel 9 by the flashing of oscillator light 17 whichhas a standard neon bulb. Resistor 61, in the oscillator circuit, is forproviding grid bias.

FIG. 7 is a simplified version of the system described in FIG. 6 withthe digit counter 14 and its associated components eliminated. Whenunits other than A of an inch for stream measurement and of an inch forrainfall are desired, the unit measurement may be altered by changingthe frequency of the oscillator connected to the thyratron tube. Thecircuit shown in FIG. 7 is, like that of FIG. 6, designed to operate inconjunction with the apparatus shown at FIGS. 2 and 3. It will be notedthat the labeling of this circuit diagram is, for the most part,identical with that of FIG. 6. These elements have been so labeled wheretheir structure and function is the same as in FIG. 6. The push buttonstarter 11 works in the same manner as in FIG. 6 to energize coil 43aand, upon release thereof, to apply current to time delay heater 45 andcoil 47b. Coil 47b keys the carrier through leads 74 and the tonegenerator through leads 75 through contacts b and 84b in the same manneras above. When the tone control relay 76 (located in a receiver used inconjunction with this invention) is closed by the reception of a signalin the receiver, coil 480 being thereby energized, opens contact 78cremoving the voltage to the ten-second delay heater 82 which eventuallyopens the automatic reset contact 83. This ten-second delay time duringwhich contact 83 is closed, must, of course, overlap the time of probestarting and the time of application of voltage to the thyratron tube 68through the relay coil 7% for the counter 13 (not shown) through leads213. In other words, the following measuring cycle takes place withinthe cooling period of heater 82. The closing of contact 490, concurrentwith the energizing of coil 48c, starts the ten cycle-persecondoscillator 81, which oscillator may also be left running free and notunder the control of contact 490. If the oscillator has been runningfree, the accuracy of the count may be afiected :plus or minus one,depending upon the part of the cycle that the oscillator is in at theinstant contact 49c is closed. Contact 490 also, in closing, sets inmotion the digit counter 13 (not shown) through leads 213 and throughcontact 862 which contact operates in conjunction with coil 79c and .25mt. condenser 80. When the tone is lost from the receiver and tonecontrol switch 76 opens, coil 48c drops out and a hundred and ten voltsis applied again through normally closed contact 780 to the heater 82.However, after the thermal time delay of contact 83 (of time delayheater 82), power is removed from coil 43a making the circuit ready forthe next cycle of operation as soon as the heater 82 has cooled and itscontact 83 has returned to the normally closed position. The drop out ofcoil 43a with normally closed contact 44a closes this circuitilluminating ready light 16. The counter utilized in this embodiment isan electromechanical four digit counter which may be operated from theplate or from a relay in the plate circuit of the thyratron 68.

Referring in detail to FIG. 8, the diagram is for an elapsed time streamwater level detector designed to work in conjunction with the controlsystems described in FIGS. 5 6, and 7. The circuit described herein islocated at the measuring site. Upon reception of tone generator signalby a receiver (not shown) from the control center, tone generatoroperated switch 91 closes and coil Ma is energized through normallyclosed time delay contact 92. This energizes the transmitter carrier(not shown) through leads 127 by the closing of contact 124a operatingfrom coil 9441. Also energized are time delay heaters 102 and 103. Timedelay heater 102 is two-second time delay and in two seconds time delaycontact 95, operating from time delay heater 192, closes, thusenergizing coil 101C through normally closed contact 96d. The energizingof coil 1010 keys the tone generator (not shown) through leads 126through contact 1230 operating from coil 1010. The closing of time delaycontact 95 also starts the probe motor 106 which is at two-hundred rpm.capacitor start and synchronously running reversible motor. Time delaycontact 92 operates from time delay heater 103 which is a five seconddelay unit. This five second delay carries the probe motor past theoperation of limit switch before timing out. The detailed operation oflimit switch )0 will be explained below. As the probe motor is operatingin forward motion, it drops the probe detector 122 suspended on thestainless steel wire 121 and, as the probe contacts the water surface,the bias of the grid in tube 115 is removed, which causes coil 11411 tobe energized, which, in turn, opens contact 9% and closes contact 98b(both contacts operated by coil 11411) to reverse the probe motor andenergize coil 107d and time delay heater 108. Tube 115 is a standarddiode-pentode operated as a diode-triode, the suppressor grid, notshown, in the pentode section being connected to the cathode. Energizingof coil itiid opens normally closed contact 96d thus dropping out coil161a. And as coil 1010 is dropped out, the tone generator, operatingthrough contact 1230, also stops. Energizing of coil tl'id also opensnormally closed contact 12551. to stop the transmitter carrier,concurrently closing contacts 7d and lead and opening contact 1120', Thereturn of the probe to home position keys limit switch 90 which is aswitch of the snap action type, operated by the gear train driven by theprobe motor. The gear train is a clock gear mechanism gearedapproximately 100 to 1. Switch 90 is actuated by a leaf lever on thesaid gear train. As limit switch 90 is thrown, a surge of DC voltage isapplied to the windings of the probe motor 166 through the seleniumrectifier 128 and contact 111 and 112d. This surge of DC voltage is toinsure an instant positive stop of the motor at the home position.Subsequently, the heater 108 will cool and thus remove the DC voltagethrough opening of time delay switch 111 operating therefrom. Contact930 operates with coil 94a to maintain the operating circuit. Normallyclosed contact 100d is operated by coil 1527a, as is contact 104d.Condenser 165 is a .9 mt. condenser. Condenser 169 is rated in thisembodiment as mf., and condenser 113 is of 10 mf. and 150 volts.Condenser 119 is a mf. condenser. The following resistors in the circuitare rated as follows: resistor 116, 15 meg.; resistor 117, 15 meg;resistor 118, 2 meg.; and resistor 12%, 10K ohms; and resistor 110 is a1K ohm lO-watt resistor.

FIG. 9 is a schematic representation of a telcmetering precipitationdevice for use at the measuring site and which may be worked inconjunction with the control systems described in FIGS. 5, 6, and 7.This circuit diagram is shown with no power applied. However, it willnormally be assumed that coil 132s is always energized except when theprobe is out of contact with water (including a situation where thebottom of the container is empty). When the tone generator controlledswitch 137 is closed upon reception of the signal by a receiver (notshown) from the control system, coil 135a is energized as is time delayheater 152. Carrier keying through leads 151 is set in operation throughthe contact 143 operating from coil 130a. Time delay cor-tact 142, whenoperated by and after the 2-second delay of time delay heater I52,energizes coil 13111 which in turn keys the tone generator (not shown)through leads 154 through contact 1441) operated by coil 13112. Also,coil 131b closes contact 13% and starts the probe motor 19 which raisesthe probe. When the probe reaches the surface of the water, coil 132C isde-energized cutting out coil 139a and keying coil 133d through theselenium rectifier 13- 3. Contact Maid of coil 133d energizes solenoidvalve 146, which is normally closed, to allow the water to drain uponcompletion of the measurement. Coil 133d is part of a time delay relaywhich is adjusted for time by resistance and capacity across the coil inorder to allow the solenoid to be open long enough to drain that amountof liquid necessary according to the type of the container in use. Asstated above, the probe 148 is in the home position at the bottom of thecontainer in contact with the mercury pool 149. When the motor pulls theprobe out of the Water and coil 132v is tie-energized, the voltage fromcoil 13th: is also removed as is the voltage to the windings of motor 19as well as carrer leads 151. The probe is then allowed to return to thebottom of the container. Motor It? is a synchronous clock motordescribed above (FIG. 4 The device shown in H6. 9 is designed to work ata time interval of 1 'ich per second in conjunction with thetclemetering indicator. Contact 1350 is a normally closed contactoperated by coil 132a. Contact 1360 is a normally open contact alsooperated by coil 132a. Passage of voltage to coil 1320 is throughselenium rectifier 1:31. It should be noted that the probe motor shaftpasses through the wall of container 18 at point 145. At this point, theshaft must be insulated in order to avoid contact with the containersince the motor shaft completes the circuit between the probe, whichmust be insulated from the container 18, and relay coil 1320. The probeis suspended in the container by suspension wire E50 Wr'ch in thisembodiment is made up of stainless stecl was. Condenser 155i is a 500mf. 150 volt condenser. Condenscr E56 is a .1 inf. condenser. It shouldbe noted that the embodiment of FIG. 8 refers to a home position abovethe water surface while the embodiment of FIG. 9 describes the homeposition as at the bottom of the container. These definitions of thehome position refer in the embodiment of FIG. 8 to a stream water leveldetector while the embodiment of FIG. 9 refers to a precipitationdetector device.

These systems are specifically designed to operate with conventionaltone generator equipment and to be transmitted by radio; however, theymay be used with wire lines as Well. All systems are designed to operatefrom a power frequency of 69 cycles and using synchronous type motors.

The invention having been described in what is considered to bepreferred embodiments thereof, it is to be understood that the specificdetails shown are merely illustrative and that various embodiments andchanges may be made without departing from its spirit and scope.

I claim:

1. In an elapsed time fluid level detection and telemetering system foruse at a measuring site and a control site, the combination ofinterrogation control means at the control site having sequentiallyoperater communication carrier and tone generator control means;interrogation transmission communication means at the control sitehaving carrier transmission means and tone generation means responsiveto said interrogation carrier and tone generator control means;communication reception means at the measuring site sensitive to saidcontrol site tone generation; liquid level measuring means at themeasuring site operating initially in response to said interrogationtone generation means and comprising an electric probe motor havingwindings, a shaft, and a pulley mounted on said shaft, a probe, andelongated elevating and lowering means for said probe operativelyattached on one end to said pulley; measuring site transmissioncommunication control means operating in conjunction with and inresponse to said liquid level measuring means having sequentiallyoperated radio carrier keying and tone generator keying means, said tonegenerator keying means operatic. simultaneously with said shaft of saidelectric probe motor in one cycle of operation of said electric probemotor; measuring site transmission communication means having carriertransmission means and tone generation means responsive to saidmeasuring site radio carrier keying and said measuring site tonegenerator keying means; communication reception means at the controlsite sensitive to said measuring site tone generation; and indicatormeans at the control site responsive to said control site communicationreception of said measuring site tone generation.

2. In an elapsed time fluid level detection and telemetering system foruse at a measuring site and a control site, the combination of claim 1wherein said measuring site transmission communication control meansfurther includes relay cutoff means for terminating said tone generatorkeying upon contact of said probe with water.

3. in an elapsed time fluid level detection and telemetering system foruse at a measuring site and a control site, the combination of claim 1wherein said measuring site transmission communication control meansfurther includes means for terminating said tone generator keying uponthe breaking of contact of said probe with water.

4. In an elapsed time fluid level detection and telemetering system foruse at a measuring site and a control site, the combination of claim 1wherein said indicator means at said control site includes dialindicators driven by motors which are operated responsivcly to saidmeasuring site tone generation means through said control sitecommunication reception means and control means for application of DCvoltage to said windings of said motors of said indicators uponcompletion of measurements.

5. In an elapsed time fluid level detection and telemetering system foruse at a measuring site and a control site, the combination ofinterrogation control means at the control site having communicationcarrier and tone generator control means, interrogation transmissioncommunication means at the control site having carrier transmissionmeans and tone generation means responsive to said control site carrierand tone generator control means, communication reception means at themeasuring site sensitive to said control site tone generation means,liquid level measuring means at the measuring site operating initiallyin response to said interrogation tone generation, measuring sitetransmission communication control means operating in conjunction withand in response to said liquid level measuring means, measuring sitetransmission communication means including carrier transmission meansand tone generation means responsive to said measuring site transmissioncommunication control means, communication reception means at thecontrol site sensitive to said measuring site tone generation, andindicator means at the control site responsive to the control sitecommunication reception of said measuring site tone generation, saidindicator means comprising at least one dial type indicator, a motoroperatively connected to said indicator operated responsively to a tonesignal, and control means for application of DC voltage to windings ofsaid motor of said indicator at the termination of said remote tonesignal.

6. In an elapsed time fluid level detection and telemetering system foruse at a measuring site and a control site, the combination of claim 1wherein said liquid level measuring means at said measuring site furtherincludes automatic control and instant stopping means for said electricprobe motor.

7. In an elapsed time fluid level detection and telemetering system foruse at a measuring site and a control site, the combination of claim 6wherein said liquid level measuring means at said measuring site furtherincludes means for selectively applying voltage to said windings of saidprobe motor in order to reverse its operation when said probe contactswater, and means for independently applying direct current voltage tosaid windings of said probe motor upon completion of the measuring cycleof said probe motor.

8. In an elapsed time fluid level detection and telemetering system foruse at a measuring site and a control site, the combination of claim 7where said means for selectively applying voltage to said windings ofsaid probe motor in order to reverse its operation when said probecontacts water, includes an electronic tube with a biased grid fromwhich the bias on said grid is automatically removed when said probecontacts water.

9. In an elapsed time fluid level detection and telemetering system foruse at a measuring site and a control site, the combination of claim 1wherein said liquid level measuring means at said measuring site furtherincludes an open top fluid measuring container having sides, a bottomportion, and support means; insulated mounting means on one of saidsides for said probe motor; a depression in said bottom portion havingtherein a mercury pool so disposed as to be directly under said probeand said pulley of said probe motor, said mercury pool being in anelectrical circuit with and a part of said automatic control and instantstopping means.

10. In an elapsed time fluid level detection and telemetering system foruse at a measuring site and a control site, the combination of claim 9wherein said liquid level measuring means at said measuring site furtherincludes a solenoid valve in said bottom portion of said measuringcontainer, automatic relay operated control means for said solenoidvalve whereby said valve opens upon completion of the measuring movementof said probe.

11. In an elapsed time fluid level detection and telemetering system foruse at a measuring site and control site, the combination of claim 1wherein said indicator means at said control site includes counter typeindicators operating responsive to said measuring site tone generationmeans through said control site communication reception means.

12. In an elapsed time fluid level detection and telemetering system foruse at a measuring site and a control site, the combination of claim 11wherein said indicator means at said control site further includescontrol means for said counter type indicators including an electrontube having a grid and an oscillator controlling said grid, said tubebeing disposed in the circuit to said counter type indicator controlmeans.

13. In an elapsed time fluid level detection and telemetering system foruse at a measuring site and a control site, the combination of claim 12wherein said indicator means at said control site further includes meansfor changing the frequency of oscillation of said oscillator.

14. In an elapsed time fluid level detection and telemetering system foruse at a measuring site and a control site, the combination ofinterrogation control means at the control site having communicationcarrier and tone generator control means, interrogation transmissioncommunication means at the control site having carrier transmissionmeans and tone generation means responsive to said control site carrierand tone generator control means, communication reception means at themeasuring site sensitive to said control site tone generation means,liquid level measuring means at the measuring site operating initiallyin response to said interrogation tone generation, measuring sitetransmission communication control means operating in conjunction withand in response to said liquid level measuring means, measuring sitetransmission communication means including carrier transmission meansand tone generation means responsive to said measuring site transmissioncommunication control means, communication reception means at thecontrol site sensitive to said measuring site tone generation, andindicator means at the control site responsive to the control sitecommunication reception of said measuring site tone generation, saidindicator means comprising at least one counter type indicator operatedresponsively to tone generated signals; and control means for each ofsaid counter type indicators including an electronic tube, having a griddisposed in a circuit connected to said counter type indicator controlmeans, and an oscillator controlling said grid.

15. The elapsed time fluid level detection and telemetering system,described in claim 14 further including means for changing the frequencyof oscillation of said oscillator.

References Cited UNITED STATES PATENTS 2,326,200 8/1943 Bristol 340-1512,748,373 5/1956 I-losmer 340-151 2,864,943 12/1958 Schultz 340-151 XFOREIGN PATENTS 215,147 11/ 1957 Australia.

WILLIAM D. MARTIN, JR., Primary Examiner.

